Effect of carbon sources on the synthesis of pectinase by Aspergilli
TL;DR: A. foetidus, NCIM 510, was the only one among the organisms studied, that responded well to the medium containing pectin in the absence of additional sugars supplied in the medium.
Abstract: The synthesis of pectinase is investigated using six species of Aspergillus, with five media differing either in their carbon sources or level of carbon source(s). Five of the six species used, synthesized appreciable amounts of pectinase in the media containing sugars. Pectinase synthesis was highest for A. niger, NCIM 548, with all the sugar containing media. A. foetidus, NCIM 510, was the only one among the organisms studied, that responded well to the medium containing pectin in the absence of additional sugars supplied in the medium.
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TL;DR: In this article, a thermophilic mold Thermomucor indicae-seudaticae was optimized in solid-state fermentation (SSF) by conventional "one variable at a time approach" and further statistically using response surface methodology.
Abstract: Glucoamylase production by a thermophilic mold Thermomucor indicae-seudaticae was optimized in solid-state fermentation (SSF) by conventional ‘one variable at a time approach’ and further statistically using response surface methodology (RSM). Glucoamylase secretion was strongly affected by three variables (moisture ratio, inoculum level and incubation time), and therefore, these three factors were further optimized using response surface methodology. The glucoamylase production in flasks containing wheat bran, under the conditions optimized by RSM, was 455 ± 23 U/g of dry moldy bran (DMB), while the predicted value by a polynomial model was 433.30 U/g DMB. The enzyme titre (455 ± 23 U/g DMB) attained in the validation experiment of this investigation is higher than those reported in the literature. When the large-scale production was attempted in enamel trays, a marginally lower enzyme titres were attained. An overall 1.8-fold increase in glucoamylase production was achieved in SSF due to statistical optimization in comparison with that of ‘one variable at a time’ approach (250 ± 13 U/g DMB). A 10-fold enhancement in glucoamylase production was recorded in SSF as compared to that in submerged fermentation.
38 citations
TL;DR: In this paper, a two-level fractional factorial design was used for screening of the most important factors among concentration of ammonium sulfate, potassium dihydrogen phosphate and date pomace, pH, total spore amount, aeration rate and fermentation time for the production of endopectinase from date pOMace by Aspergillus niger PC5.
32 citations
TL;DR: In this paper, the authors focused on the utilization of fruit and agro-industrial wastes for the production of yeast pectinases using response surface optimization techniques and found that OP (5), GC (4), MnSO4 (0.08%, w/v) and IP (48h) were significant parameters for pectase production.
Abstract: The present study is focused on the utilization of fruit and agro-industrial wastes for the production of yeast pectinases using response surface optimization techniques. Orange peel (OP), groundnut oil cake (GC), MnSO4 and incubation period (IP) were found as significant parameters for pectinase production. The central composite design of media optimization indicated that OP (5), GC (4), MnSO4 (0.08%, w/v) and IP (48 h) increased the pectinase production by 9-fold. Crude pectinase promoted the enzymatic peeling of oranges and processing of raw banana fibers. Topographical changes of enzyme treated orange and mango peels were studied using AFM which provides a new tool to unravel the role of pectin aggregation in the dissolution of middle lamella during enzymatic hydrolysis. Changes in the fingerprint regions of enzyme treated fruit substrates were observed along with the disappearance of the impurities such as waxes and pectin using FTIR spectral analysis.
25 citations
TL;DR: In this article, a solid state culture conditions for polygalacturonase production by Fusarium moniliforme from dried mango peel powder were optimized by Taguchi's L-18 orthogonal array experimental design methodology.
Abstract: Mango peel is one of the major wastes from fruit processing industries, which poses considerable disposal problems and ultimately leads to environmental pollution. The objective of the current research was to determine the significant parameters on the production of polygalacturonase from mango peel which is a major industrial waste. Solid state culture conditions for polygalacturonase production by Fusarium moniliforme from dried mango peel powder were optimized by Taguchi’s L-18 orthogonal array experimental design methodology. Eight fungal metabolic influencing variables, viz. temperature, mango peel, inoculum, peptone, ammonium nitrate (NH4NO3), magnesium sulphate (MgSO4), zinc sulphate (ZnSO4) and potassium dihydrogen phosphate (KH2PO4) were selected to optimize polygalacturonase production. The optimized parameters composed of temperature (30°C), mango peel (6.5%, g, w/v), inoculum (8%, ml, v/v), peptone (1%, g, w/v), NH4NO3 (0.60%, g, w/v), MgSO4 (0.05%, g, w/v), ZnSO4 (0.06%, g, w/v) and KH2PO4 (0.4%, g, w/v). Based on the influence of interaction of fermentation components of fermentation, these could be classified as the least significant and the most significant at individual and interaction levels. The temperature, inoculum level, mango peel substrate and KH2PO4 showed maximum production impact at optimized conditions. From the optimized conditions the polygalacturonase activity was maximized to 43.2 U g−1.
23 citations
Cites background from "Effect of carbon sources on the syn..."
...Temperature, incubation time, pH and level of pectin as carbon source are the major environmental factors affecting polygalacturonase production in fungal pathogens (Yakoby et al. 2000; Nair et al. 2004 )....
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01 Oct 2014
TL;DR: Orange peel as pectin source, casein hydrolysate as nitrogen source and NaCl showed maximum enzyme production and so were selected for further quantitative optimization in polygalacturonase production.
Abstract: Selection of the best nutrients is one of the most critical stage in media optimization for polygalacturonase production. Plackett-Burman design was used to screen various pectin substrates, nitrogen sources and mineral nutrients for polygalacturonase production by Aspergillus awamori MTCC 9166. Fifteen different pectin sources like crude pectin, polygalacturonic acid, orange peel, citrus peel, jackfruit peel, etc. were selected for polygalacturonase production using 16 experimental design of Plackett-Burman. Similarly, eleven nitrogen sources like yeast extract, tryptone, casein hydrolysate, sodium nitrate, ammonium chloride, etc. and eleven mineral nutrients like NaCl, MgSO4, KH2PO4, CaCl2, etc. were screened for polygalacturonase production using 12 experimental design of Plackett-Burman. The enzyme production was studied for 5 d, where the maximum production was observed on 3 d and so this data was analyzed using Indostat software to obtain regression coefficients and t-values. Based on these values significant nutrients like seven pectin sources (orange peel, jack fruit rind, apple peel, pine apple peel, mango peel, banana peel & tomato pulp), four nitrogen sources (urea, yeast extract, casein hydrolysate & potassium nitrate) and four mineral nutrients (NaCl, KH2PO4, CaCl2 & KH2PO4) were selected for second level screening of efficient nutrients for polygalacturonase production using 16 experimental design of Plackett-Burman. Orange peel as pectin source, casein hydrolysate as nitrogen source and NaCl showed maximum enzyme production and so were selected for further quantitative optimization.
11 citations
References
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TL;DR: Three assay procedures are described that permit quantitative assay of hydrolytic and β-eliminative pectic enzymes, respectively, and can guide purification strategies, particularly when used in conjunction with titration curves.
Abstract: Publisher Summary The characterization and purification of a pectic enzyme is often complicated by the presence of other pectic enzymes produced by the source microorganism. This chapter describes three assay procedures that address this problem. Pectic enzymes from Erwinia spp. is used as examples in the chapter. The assays are readily adapted to the analysis of pectic enzyme complexes of other organisms and can be used with crude preparations. Results from plant tissue extracts should be interpreted cautiously, however, because of the prevalence of pectic enzyme inhibitors. The activity stains in the first procedure enable rapid approximation of the number and type of pectic enzymes in the sample and can guide purification strategies, particularly when used in conjunction with titration curves. The second and third procedures permit quantitative assay of hydrolytic and β-eliminative pectic enzymes, respectively. The action patterns of purified pectic enzymes are determined by viscometric and reaction product analyses; oligogalacturonides are resolved by paper chromatography or thin-layer chromatography and detected with bromphenol blue or thiobarbituric acid spray reagent.
303 citations
TL;DR: Results indicate that regulatory phenomena, such as induction-repression or activation-inhibition, related to pectinase synthesis by A. niger CH4 are different in the two types of fermentation.
Abstract: A study was made to compare the production of pectinase by Aspergillus niger CH4 in solid-state (SSF) and submerged (SmF) fermentations. Production of endo- (endo-p) and exo-pectinase (exo-p) by SSF was not reduced when glucose, sucrose or galacturonic acid (up to 10%) were added to a culture medium containing pectin. Moreover, both activities increased when concentrations of the carbon sources were also increased. In SmF, these activities were strongly decreased when glucose or sucrose (3%) was added to culture medium containing pectin. The addition of galacturonic acid affected endo-p activity production to a lesser extend than exo-p. Final endo-p and exo-p activities in SSF were three and 11 times higher, respectively, than those obtained in SmF. The overall productivities of SSF were 18.8 and 4.9 times higher for endo-p and exo-p, respectively, than those in SmF. These results indicate that regulatory phenomena, such as induction-repression or activation-inhibition, related to pectinase synthesis by A. niger CH4 are different in the two types of fermentation.
218 citations
TL;DR: A process was developed for the production of polygalacturonase by Aspergillus niger and its mutant VTT-D-77050 and the enzyme mixture produced in one pilot fermentation was used successfully for improving the cloud stability of fruit nectars.
106 citations
"Effect of carbon sources on the syn..." refers background in this paper
...Although many yeasts, some bacteria and a large variety of filamentous fungi are known to synthesize pectic enzymes, the most preferred industrial choice rests on fungi of the genus Aspergillus [ 1 , 2]. Another important factor influencing the synthesis of pectic enzymes in the mixture is the medium composition, particularly the carbon and nitrogen sources [3, 4]. Studies have been conducted by different workers using both synthetic and ......
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TL;DR: This review deals mainly with the literature which has appeared since the discovery of pectin lyases in 1960 and it is emphasized that the choice of substrates and reaction conditions, as well as that of methods of analysis, to a large extent influence the values found for a number of enzyme properties.
Abstract: This review deals mainly with the literature which has appeared since the discovery of pectin lyases in 1960. Those papers have been selected which are reports of investigations carried out with purified enzyme preparations and rather well defined substrates. According to their action on high polymer pectic substances, the enzymes are placed in one of six different groups. Mutual relationships of some of the groups are discussed. It is emphasized that the choice of substrates and reaction conditions, as well as that of methods of analysis, to a large extent influence the values found for a number of enzyme properties. Trends for future research are outlined.
80 citations
01 Mar 1978
TL;DR: It is suggested that catabolite repression of polygalacturonase occurs at the level of translation and that of acid protease at transcription in an adenine-requiring mutant of Aspergillus niger.
Abstract: A comparative study was made on catabolite repression of acid protease and polygalacturonase in an adenine-requiring mutant of Aspergillus niger. Both enzymes are inducible and accumulated extracellularly after cessation of growth caused by adenine starvation. Addition of glucose, fructose, or intermediates of glycolysis, but not tricarboxylic acid cycle intermediates, depressed the formation of both enzymes. Catabolite repression of polygalacturonase by glucose occurred quickly and was almost complete. However, acid protease was only partly repressed even after several hours. Formation of polygalacturonase in the presence of actinomycin S3 or during deinduction was repressed by glucose, whereas that of acid protease was not. In the course of induction of acid protease by peptone, glucose did not affect the length of the induction lag period and the rate of acid protease formation decreased by glucose was not restored by the addition of large amounts of inducer. From these results, we suggest that catabolite repression of polygalacturonase occurs at the level of translation and that of acid protease at transcription.
33 citations